You're better off just revisiting Xenoblade Chronicles, a game that greatly influenced JRPGs more than Final Fantasy XIII, and for good reason. Hell, it even inspired Final Fantasy XV more than Final Fantasy XIII (which was originally Versus XIII a linear game and changed to XV an open world game).
What can be said about XIII beyond the fact it's the first single player Final Fantasy without any of the most influential creators save Namura and the guy who makes the score of Final Fantasy, not that you'd even know because most of the music isn't an updated or different approach to any of the old Final Fantasy music (at least in the first XIII, I played part 2 for a handful of hours and barely touched XIII-3 at all, but I did beat XIII). Not to mention the music shoved in everyone's face in advertising was a Leona Lewis "My Hands" song not even in the Japanese version if I'm not mistaken. But let's move on.
What can be said about XIII (at least the original) that fits more perfectly than style over substance. You'll notice when you look at everything, it looks very good, too bad there just isn't much to do here. What do I mean by that? I mean roles that you level up are just as linear as the game itself. You choose the role you want to level up, then it has a skill tree that is mostly line to line leveling based on how many skill points you have. And they are mostly exactly the same for every character, bar a few branches (and by this I usually mean literally one additional skill you can choose either or then back to the straight line path) you go from skill to skill in a straight line. Oh, and the ones who get the very few additional skills are people who are naturally leaning toward that class. Like Lightning (and I almost threw up in my mouth a little just typing the name) will have 2 or 3 additional soldier skills than Hope, while hope will have a few more saboteur skills than Lightning. Mostly negligable though, and the actual skill tree is pretty sparse even if the character gets the few extra skills.
Beyond the level system, the combat's pretty shallow, and if you Libra the enemy the game can literally play itself. (Libra detects the skills most damaging to an enemy, and there is an auto battle function which will do everything to include changing the classes of you characters back and forth to heal, etc.) As for customization you get to add two accessories and a weapon... and that's it. And you can either buy these weapons from floating orbs that act like "shops" or you can use materials to create new weapons. I made a weapon with parts once, that's it, and I bought weapons every time an orb came up and I beat the game with absolutely no problem. And that about it for your character. The only aesthetic changes that can be made to your guy btw is the weapon (a bit, it mostly just changes color) and your two accessories (like Lightnings earrings will change from blue to black).
As far as the world, it may look cool, but looking cool is all it will ever do (again for the original XIII) No real interaction with towns, there's even a Gold Saucer like area you go to (forget the name) and there is literally nothing you you to do there. The entire world is just a pretty back drop... And that's it, nothing else to really say about the world.
And God there is SO much more I could write. It's a game specifically made for it's visuals, and they don't hold up. That's what I'm gonna leave it on. Again at least as far as the first XIII which is the one I really know.